The Clinical Core provides the Projects with clinical, medical, neuropsychological and epidemiological data as well as clinical outcomes including diagnoses and Clinical Dementia Rating. The Clinical Core is responsible for obtaining consents for study participation and for autopsy, collecting and banking blood, and conducting diagnostic assessments. The specific aims are to enroll a population-based sample form the Health Care Financing Administration roster for local zip codes and to enroll additional volunteers who specifically consent to autopsy. The Clinical Core triages study participants to Projects 2 and 3 and tracks all study participants to ensure continued follow-up. All subjects are administered an in-person Clinical Core evaluation at baseline, and subsequent 18-month intervals and when cognitive impairment is detected. The Clinical Core is also responsible for coordinating data collection from Mayo-Clinic Jacksonville for Florida subject included in Project 3, and for collecting follow-up information about those study subjects who no longer return for in-person evaluation. Baseline blood samples are tested for ApoE status and banked for future genetic testing. Diagnostic work-ups (neuroimaging and blood testing) are obtained when clinically indicated. Case conferences are held to assign clinical outcomes for each subject at each wave. Clinical outcomes include: 1) Diagnosis of DSM-III-R and DSM-IV Dementia versus 'No Dementia', 2) Dementia subtype for demented subjects, 3) Clinical Dementia Rating (CDR) and Mild Cognitive Impairment (MCI) status, and 4) Documentation of significant life transitions (e.g., nursing home placement).